In one common form of battery comprising a calcium cell, air agitation of the electrolyte is required. It is conventional to provide means for continuously pumping air through the electrolyte to prevent stratification thereof. It is conventional to provide a relatively low rate, such as 0.03 CFM of air delivery through a supply tube from the ambient atmosphere.
A problem arises in the need for periodically replacing the air supply tube which extends outwardly through a coupling nut for conducting the desired air to a supply barrel of an airlift pump within the battery. In one conventional prior art battery utilizing such an air supply means, as illustrated in FIG. 3 of the drawing, the battery generally designated 10 is provided with a flash arrester generally designated 11 removably carried on the cover 12 closing the upper open end of the case, or jar, 13 of the battery. The coupling nut 14 is then removed. The removal of the flash arrester assembly permits the insertion of the serviceman's hand through the resulting opening, permitting the hand to be used to guide a replacement air supply tube 15 being fed through the opening resulting from the removal of the coupling nut 14. The user must guide the tube 15 into a small opening 16 in the airlift pump generally designated 17, which is not only difficult, but also hazardous because of the presence of the electrolyte and the current producing capabilities of the cell.
A battery charging system for use in submarines and the like is disclosed in U.S. Pat. No. 3,040,116 as having an air supply tube extending downwardly through a cap into a percolator tube. Air passing downwardly through the supply tube bubbles upwardly through the electrolyte in the percolator tube, thereby causing circulation and agitation of the electrolyte. The continuous internal agitation and recirculation of the electrolyte in the battery is intended to enable a fast charging of the battery with a rapid release of hydrogen gas therefrom to be burned by the submarine engine. As specifically disclosed by Gauvin, the agitation and recirculation of the electrolyte overcomes any stratification of the electrolyte where the more dense, or higher specific gravity electrolyte formed during charging tends to accumulate at the bottom of the cell. The percolator tube is provided with a top member which has a small opening through which the air supply tube must be inserted and, thus, Gauvin illustrates the problem in the prior art of the air tube replacement discussed above.